Tow guide for stuffer box crimping

ABSTRACT

Method and apparatus are disclosed for stuffer crimping a filament or fiber tow of at least 5,000 total denier. The tow is fed between the teeth of at least one pair of meshing gear wheels, the teeth of the gear wheels applying simultaneous transverse forces to the tow.

United States Patent 1191 Heijnis June 4, 1974 TOW GUIDE FOR STUFFER BOX 2,419,320 4/1947 Lohrke 28/7214 x 3,192,597 7/1965 McIntosh et al..... 28/].8 CRIMPING 3,213,075 1 1965 Hendrix 28/l.6 5] Inventor: James W. L]. Henms, r 3,220,083 11/1965 Crawford et al .1 28/l.6 Netherlands 3,234,626 2/1966 Faria 28/1 .3 [73] Assignee: Akzona Incorporated, Asheville,

NC. Primary Examiner-Louis K. Rimrodt [22] Filed: 22, 1971 Att0rney,Agent, or F irm-Francis W. Young; Tom R. 21 Appl. No.: 126,482 Ye V g [30] Foreign Appllcation Prlorlty Data ABSTRACT Mar. 25, 1970 Netherlands 7004249 [52] US. Cl. 28/l.6 Method and apparatus are disclosed for Swffer p- 51 1111. C1 D02g 1/12 ing a filament or fiber w of at least 5,000 total [58] Field of Search 28/1 CF, 1.3, 1.6, 1.8, nier- The tow is fed between the teeth of at least one 28/7111; 19/ 5 T pair of meshing gear wheels, the teeth of the gear wheels applying simultaneous transverse forces to the [56] References Cited UNITED STATES PATENTS 2,3l 1,174 2/l943 Hitt 28/l.6

4 Claims, 4 Drawing Figures 'IIIII llllllli mememuu 4 mm 35813740 VIII'IIIII v v v 'IIIIIJ 'llllllll;

INVENTOR JAMES W.- IJ. HEIJNIS ATTORNEY TOW GUIDE FOR STUFFER BOX CRIMPING This invention relates to a method and apparatus for crimping a filament tow or fiber tow having a total denier of at least 5,000.

In the art of crimping filament or fiber tow, it is known to feed the tow through one or more pairs of rolls into and through a confined chamber where the tow is crimped before being withdrawn from the chamber. Often a heated medium such as steam is allowed to enter into the chamber with the crimped tow to permanently set the crimp in the individual filaments or fibers.

It is desirable to control the parallel alignment of each filament or fiber of the tow as it enters the crimping chamber so that uniformity and crimp eveness may be maintained in the finished product. A known method of aligning the tow requires separating the tow into smaller segments and recombining the segments, requiring an intricate feeding during start-up. Another method feeds the tow over a series of flanged rollers to converge the tow into the appropriate web shape. However, it has been found these methods still lack the desired optimum parallel alignment of the fibers or filaments in the tow.

Therefore, an object of this invention is to provide a method for placing the filaments or fibers of a tow of 5,000 denier or more into parallel alignment to insure uniformity and eveness of crimp of the tow in a crimping housing.

The present invention feeds the tow to be crimped through means that simultaneously exert transverse forces on the tow to align the individual elements of the tow prior to their entry into the crimping housing. This may be accomplished according to the preferred apparatus of the invention by feeding the tow between one or more groups of intermeshing gear wheels, the midregion of the teeth of said wheels being at a lower height than the teeth edges. This may be explained by reference to the accompany figures.

FIG. 1 is an elevational view of an apparatus for the stuffer box crimping ofa tow.

FIG. 2 shows. in section. part of the gear wheels on an enlarged scale.

FIG. 3 is a sectional view along the line III III in FIG. 2.

FIG. 4 shows a different embodiment of the combination of gear wheels.

In FIG. 1, an endless tow I, which may be composed of a plurality of bundles, is passed between three successive pairs of intermeshing gear wheels 2, 3 and 4. It can be seen from FIG. 2 that, in the mid-region of the gear wheels, the teeth 5 are ofa reduced height 6, while the teeth at the sides, or end faces, of the wheels are of normal height 7. In the mid-region of the gear wheels, the tips of the teeth of height 6 extend only to approximately the circumference of the pitch circle with the radius 8. Here, the teeth 5 repeatedly apply transverse forces to the thickest portions of the tow l lying in the approximately trapezoidal-shaped recesses of the teeth (see FIG. 3). As the sides of the teeth are of normal height, these sides form toothed flanges that enclose the tow 1 from the sides.

After the tow has left the last pair of gear wheels 4, it passes to the stuffing rolls 9 in a direction which is virtually perpendicular to the plane through the gear wheels 4. The stuffing rolls 9 may be in the form of smooth cylindrical rolls of approximately mm in diameter. These rolls are forced towards each other by spring action, as they feed the tow 1 against a wad of stuffed tow already present in the stuffer box I0. At the outlet of the stuffer box 10 is a hinged door 11, which is loaded by a weight 12 in order to obtain the desired buckling pressure.

FIG. 4 shows a modified arrangement of the gear wheels. The tow I travels over a guiding roller 13 to a central gear wheel 14 of relatively large diameter. Gear wheel 14 meshes with three relatively smaller gear wheels l5, l6, and 17; these three wheels being spaced some distance apart on the periphery of wheel 14. It is not necessary that the peripheral wheels be smaller than the central wheel, however.

The teeth of the gear wheels 14, 15, I6 and 17 may have trapezoidal recesses similar to those provided in the teeth of gear wheels 2, 3, and 4 of FIGS. 1, 2, and 3. After the tow has passed the gear wheel 17, it travels to the rolls of a stuffing box crimper similar to FIG. 1.

Various adaptations can be made from these basic embodiments. For example, the cross-section of the recess in the teeth of each successive group may be varied progressively from a circular cross section, for instance, down to the final preferred trapezoidal shape before being fed to a stuffer crimper device. This can be especially advantageous in forming a tow of the larger total deniers.

What is claimed is:

'1. Apparatus for stuffer box crimping a filament tow of at least 5,000 total denier, comprising:

a. means for feeding the tow through an alignment region;

b. at least one pair of intermeshing toothed gear wheels, the mid-region of the gear wheel along the face width of the teeth being recessed below the outer edges, said toothed gear wheels operable to apply transverse forces to a tow to place the filaments in parallel alignment;

c. a crimping chamber for receiving the parallel filaments and imparting a crimp to-the tow; and

d. stuffer rollers for feeding the tow from the alignment zone to the crimping chamber.

2. The apparatus of claim 1 wherein the recessed midregion of the teeth extends approximately to the circumference of the pitch circle of the teeth edges.

3. The apparatus of claim 2 wherein the cross section formed by the intermeshed recessed teeth is trapezoidal.

4. The apparatus of claim I wherein there is provided successive pairs of intermeshing gear wheels whose recessed teeth vary, in order, from an approximate circular cross section to a trapezoidal cross section. 

1. Apparatus for stuffer box crimping a filament tow of at least 5,000 total denier, comprising: a. means for feeding the tow through an alignment region; b. at least one pair of intermeshing toothed gear wheels, the mid-region of the gear wheel along the face width of the teeth being recessed below the outer edges, said toothed gear wheels operable to apply transverse forces to a tow to place the filaments in parallel alignment; c. a crimping chamber for receiving the parallel filaments and imparting a crimp to the tow; and d. stuffer rollers for feeding the tow from the alignment zone to the crimping chamber.
 2. The apparatus of claim 1 wherein the recessed midregion of the teeth extends approximately to the circumference of the pitch circle of the teeth edges.
 3. The apparatus of claim 2 wherein the cross section formed by the intermeshed recessed teeth is trapezoidal.
 4. The apparatus of claim 1 wherein there is provided successive pairs of intermeshing gear wheels whose recessed teeth vary, in order, from an approximate circular cross section to a trapezoidal cross section. 